Lotus 1-2-3 1.0A for TI Professional Computer Released in 1983 by Lotus Development Corporation For DOS on the Texas Instruments Professional Computer ONLY Image Quality: Unmodified This is an adaptation of Lotus 1-2-3 1A specifically for the Texas Instruments Professional Computer. The TI Professional Computer is a non-IBM PC hardware compatible computer that runs an adaptation of MS-DOS. Important: This release will NOT run on an IBM PC computer, IBM PC clones, or IBM PC emulators. Important: This software is copy protected, and no unprotect is known to exist. Protection type: A mis-numbered extra sector on tracks 0 and 1, head 0. This disk set happened to include an IBM PCJr driver installation disk. This disk would be used on a standard Lotus 1-2-3 1.0a system disk to enable IBM PCJr compatibility (without having to use the ROM cartridge version). It is not quite clear if this disk could be used with the TI Professional Computer version for this purpose.